Bi-directional transfer of media content assets in a content delivery network

ABSTRACT

Systems, apparatuses, methods, and software for using a network to efficiently distributing media content assets from a virtually unlimited content library and/or other storage to a plurality of client devices, as well as bi-directional local content sharing between head ends, and dynamic distribution and generation of media content assets within the network.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. provisional patentapplication Ser. No. 61/165,197, filed Mar. 31, 2009, entitled “BuildingLarge VOD Libraries With Next Generation On Demand Architecture,” herebyincorporated by reference as to its entirety.

BACKGROUND

Increasingly, cable operators are using video-on-demand (VOD) as acompetitive advantage. Alternative video delivery methods such as moviedownload or video streaming via the Internet are also becoming morepractical and feasible as service providers deploy either DOCSIS 3.0wideband or fiber-to-the-home technologies.

Using the existing managed network approach that is adopted by variouscable and telephone network operators, VOD content is typically encodedin MPEG-2 format and replicated/pushed along with metadata via asatellite or Internet Protocol (IP) backbone to local VOD systems.However, this approach does not necessarily scale well as the amount ofavailable content increases. For instance, as the network grows and theamount of VOD content expands, it quickly becomes overly burdensome onthe network to replicate all of the content out to local VOD systems.

In an alternative emerging “over-the-top” approach, the broadbandInternet is typically used as the content distribution and streamingplatform. In this approach, content aggregators and integrators licenseand publish movies and television shows via Internet websites. Clientdevices such as set-top boxes may be able to access media content viathe Internet using a broadband pipe such as via a cable modem, DSLconnection, or fiber-to-the-home (FTTH) network. Content distributionwithin the Internet is often driven by a “pull” model in response toclient device requests.

However, there are several limitations of this over-the-top approach.For instance, it may be difficult to achieve high concurrency forhigh-definition (HD) VOD streaming, and this approach relies on publicInternet infrastructure that imposes quality of service constraints,which may result in substantial network congestion. Moreover, there istypically a lack of end-to-end network resource management, as well asinconsistent premium content offerings due to lack of programmingagreements with content providers. In addition, a pure over-the-topapproach typically requires subscribers to purchase a separate clientdevice appliance for viewing VOD assets.

There are significant opportunities for network operators to expand thecurrent VOD architecture in order to support larger VOD contentlibraries that provide an expansive amount of content, and to providethe VOD offerings to devices other than conventional set-top boxes, suchas personal computers and portable media players. Such a newarchitecture may be capable of handling larger non-VOD content librariesas well.

SUMMARY

An integrated video-on-demand (VOD) content library platform may beprovided that supports virtually an unlimited amount of media contentassets such as movies, television shows, Internet video, anduser-generated content. This approach may combine features of existingmanaged network approaches with emerging over-the-top approaches, byintroducing a content delivery network that has a large content library,typically made up of smaller libraries interconnected together and withcontent providers and local head ends via a high-speed backbone, such asan Internet Protocol (IP) backbone, and/or via regional networks.

The content delivery network may enable operators to cost-effectivelyprovide a much larger amount of media content, such as VOD content, byserving at least some of the content from national and regionallibraries instead of replicating all content to the local distributionsystems (e.g., head end systems) as is conventionally done. Intelligentcaching may be used by the content delivery network and/or by the localsystems, where the caching locations and caching timeframes for eachpiece of content may be based on such priority factors as the actual orexpected popularity (global or local) of the content, the actual orexpected usage (global or local) of the content, the quality of service(QoS) of the content, the data size of the content, storage andresponsiveness expectations defined by service-level agreements (SLAs),the demographics of the expected audience for the content, and theidentity of the provider or owner of the content. Such intelligentcaching may be expected to reduce network bandwidth usage and enhanceoverall service performance by potentially reducing the amount ofredundant storage and transfer that would ordinarily be needed as theamount of available content increases.

As a default, most content may be stored in the main content library.Then, depending upon content popularity and/or other factors, thecontent may be replicated and propagated ahead of time, or in responseto a client request, to or near one or more of the local head endsystems. Upon a subscriber's request for content, the local systemserving that subscriber may begin immediately streaming the content ifthe content is already cached at the local system. If the content is notcached at the local system, then the local system may pull the contentfrom the content library or elsewhere. The pulled content may thereaftercontinue to be cached at the local system for a period of time to serveexpected future requests from other subscribers served by that localsystem, and then later removed if desired.

In addition, certain content, such as trick files, may be generateddynamically as needed. In this way, it is not necessarily topre-generate and pre-store all possible trick files for real-time andnon-real-time content.

And, because not all content will necessarily be stored at all localregions of the network, a bi-directional transfer of content betweenlocal regions of the network may be provided for. For example, a firsthead end system may not only receive content downstream from the mainnetwork, but may also send content upstream through the network toanother head end system requesting the content.

Thus, some aspects as described herein may be directed to systems,apparatuses, methods, and software for receiving from a first clientdevice a first request for a media content asset; responsive to thefirst request, determining whether the media content asset is stored ata first location in a network; responsive to determining that the mediacontent asset is not stored at the first location, fetching the mediacontent asset from a second location in the network and storing themedia content asset in a computer-readable medium at the first location;streaming to the first client device the media content asset stored atthe first location; and responsive to a second request from a secondclient device, streaming to the second client device the media contentasset stored at the first location.

Further aspects are directed to systems, apparatuses, methods, andsoftware utilizing a network storing a plurality of media contentassets, for determining a popularity of each of the media contentassets; and for each of the media content assets, replicating the storedmedia content asset to a particular computer-readable medium in thenetwork that depends upon the determined popularity for that mediacontent asset.

Still further aspects are directed to systems, apparatuses, methods, andsoftware for receiving a request for a first media content asset;determining whether the first media content asset is already stored; andresponsive to determining that the first media content asset is notalready stored, generating by a computer the first media content assetfrom a stored second media content asset.

Yet further aspects are directed to systems, apparatuses, methods, andsoftware for receiving first media content and associated first metadataat a first video-on-demand system, the first video-on-demand systembeing configured to stream media content assets to a first plurality ofclient devices; storing, by the first video-on-demand system, a firstmedia content asset in a first computer-readable medium; and sending, bythe first video-on-demand system, the first metadata to a database,wherein the database is accessible by a second video-on-demand systemconfigured to stream media content assets to a second plurality ofclient devices to which the first video-on-demand system is notconfigured to stream media content assets.

These and other aspects of the disclosure will be apparent uponconsideration of the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present disclosure and thepotential advantages of various aspects described herein may be acquiredby referring to the following description in consideration of theaccompanying drawings, in which like reference numbers indicate likefeatures, and wherein:

FIG. 1 is a functional block diagram of an illustrative content deliverynetwork 100 and surrounding environment.

FIG. 2 is another illustrative functional block diagram of a portion ofcontent delivery network 100 in conjunction with head ends and clientdevices.

FIG. 3 is a diagram of illustrative interactions between variouselements of a content delivery network and its environment, whenperforming ingest of non-real-time media content assets.

FIG. 4 is a diagram of illustrative interactions between variouselements of a content delivery network and its environment, whenperforming ingest of real-time media content assets.

FIG. 5 is a diagram of illustrative interactions between variouselements of a content delivery network and its environment, whenpre-positioning a media content asset already stored in a contentlibrary to a replicated location.

FIG. 6 is a diagram of illustrative interactions between variouselements of a content delivery network and its environment, whenstreaming content to a client device in response to a request from theclient device.

FIG. 7 is a diagram of illustrative interactions between variouselements of a content delivery network and its environment, when apre-stored trick file is requested to be streamed to a client device.

FIG. 8 is another diagram of illustrative interactions between variouselements of a content delivery network and its environment, when a trickfile that has not yet been created is requested to be streamed to aclient device.

FIG. 9 is a functional block diagram of an example of how a contentdelivery network may be used to perform bi-directional local contentsharing between head ends.

FIG. 10 shows illustrative interactions between various equipment when alocal media content asset is shared between streaming servers of twodifferent head ends.

DETAILED DESCRIPTION

FIG. 1 is a functional block diagram of an illustrative content deliverynetwork 100 and surrounding environment. In this example, contentdelivery network 100 includes a content library 101, a caching gateway102, a content propagation manager (CPM) 103, a content library service(CLS) 104, a content ingest block 105, and a real-time ingest block 106,each being communicatively coupled to each other (bidirectionally orunidirectionally as desired) in the manner shown in FIG. 1.

Content delivery network 100 in this example may be communicativelycoupled to (again, bidirectionally or unidirectionally as desired) thefollowing functional blocks: a content ingest manager 107, a transcoder108, a derived content generator 109, a real-time manager 110, a rightsmanagement system (RMS) 111, a content management system (CMS) 112, ametadata distribution hub (MD H) 113, an asset management system (AMS)114, one or more video-on-demand (VOD) backoffices 115, one or more edgeresource managers 116, one or more streaming servers 117, one or moreedge quadrature amplitude modulation (QAM) units 118, one or morestaging servers 119, one or more cable modem termination systems (CMTSs)120, a data warehouse server 121, and a network management system 122Together, VOD backoffices 115, edge resource managers 116, streamingservers 117, edge QAMs 118, staging servers 119, and CMTSs 120 may beconsidered as one or more head ends 190 for content delivery network100.

Content delivery network 100 may be any type of network, and may be asingle network or a combination of multiple networks, such as atelevision distribution network, a telephone network, and/or theInternet. Physically, content delivery network 100 may be embodied asmultiple computers communicatively coupled together in a wired and/orwireless manner. Content delivery network 100 may also becommunicatively coupled to a plurality of end-user client devices 201A-H(FIG. 2) in a wired and/or wireless manner, such as via coaxial cable,optical fiber, hybrid-fiber-coaxial cable, and/or cellular data ortelephone links. While content delivery network 100 is shown toencompass certain functional blocks and not other functional blocks, itis noted that this division may be functional rather than necessarilyphysical, and somewhat arbitrary. Thus, content delivery network 100 mayalternatively include others of the functions shown in FIG. 1. Forinstance, head ends 190 may be considered part of content deliverynetwork 100. Alternatively or additionally, some of the functionalblocks shown in FIG. 1 as part of content delivery network 100 may beconsidered outside of content delivery network 100.

Any of the above-mentioned functional blocks 101-122 may each beimplemented, for example, as a computer or as a system or device thatincludes a computer. The term “computer” as referred to herein broadlyrefers to any electronic, electro-optical, and/or mechanical device, orsystem of multiple physically separate or physically joined suchdevices, that is able to process and manipulate information, such as inthe form of data. Non-limiting examples of a computer include one ormore personal computers (e.g., desktop or laptop), servers, smartphones, personal digital assistants (PDAs), television set top boxes,and/or a system of these in any combination or subcombination. Inaddition, a given computer may be physically located completely in onelocation or may be distributed amongst a plurality of locations (i.e.,may implement distributive computing). A computer may be or include ageneral-purpose computer and/or a dedicated computer configured toperform only certain limited functions.

A computer typically includes hardware that may execute software and/orbe configured in hardware to perform specific functions. The softwaremay be stored on a computer-readable medium in the form ofcomputer-readable instructions. A computer may read thosecomputer-readable instructions, and in response perform various steps asdefined by those computer-readable instructions. Thus, any functionsattributed to any of functional blocks 101-122 as described herein maybe implemented, for example, by reading and executing suchcomputer-readable instructions for performing those functions, and/or byany hardware subsystem (e.g., a processor) from which the computer iscomposed.

The term “computer-readable medium” as used herein includes not only asingle physical medium or single type of medium, but also a combinationof one or more physical media and/or types of media. Examples of acomputer-readable medium include, but are not limited to, one or morememories, hard drives, optical discs (such as CDs or DVDs), magneticdiscs, and magnetic tape drives.

Such a computer-readable medium may store computer-readable instructions(e.g., software) and/or computer-readable data (i.e., information thatmay or may not be executable). In the present example, acomputer-readable medium (such as memory) may be included in any one ormore of functional blocks 101-122 and may store computer-executableinstructions and/or data used by any of those blocks 101-122.Alternatively or additionally, such a computer-readable medium storingthe data and/or software may be physically separate from, yet accessibleby, any of blocks 101-122.

In general, content delivery network 100 is configured to receive aplurality of media content assets, store the media content assets invarious distributed locations such as content library 101, one or morecaching gateways 102, and/or one or more head ends 190 such as one ormore streaming servers 117. Content delivery network 100 is furtherconfigured to forward selected ones of the media content assets to endusers via edge QAMs 118. In other embodiments, media content assets maybe streamed to client devices 201 by other additional or alternativemeans, such as over the Internet or over a cellular data network. Insuch a case, QAMs 118 may be replaced or augmented with other devicesappropriate for providing the requested media content assets to clientdevices 201. Each media content asset may be stored at a single locationwithin content delivery network 100 and/or head ends 190, or replicatedamong multiple different locations within content delivery network 100and/or head ends 190.

A “media content asset” is any unit of media content that includes audioand/or video content. As used herein, the term, “video content asset,”is a media content asset that includes video content and may optionallyalso include audio content. Likewise, an “audio content asset” is amedia content asset that includes audio content and may optionally alsoinclude video content. Examples of a media content asset includes,without limitation, movies, television programs, news programs,advertisements, video clips, audio (e.g., radio) programs, audio clips,and trick files. Media content assets may include live content (e.g., alive sports game) and/or pre-recorded content, and may include VODcontent or pre-scheduled broadcast content. A media content asset mayalso be associated with or include metadata that is descriptive of themedia content asset and/or the content therein. For example, suchmetadata may include or otherwise indicate a description of the contentin the media content assets, a date or date range of the content, a timelength of the content, a data size of the content, a format of thecontent, a bit rate of the content, etc.

Referring again to FIG. 1, one or more content providers provide mediacontent assets in the form of files (typically for non-real-timecontent) and/or streams (typically for real-time content), along withany associated content metadata to transcoder 108, which may transcodethe incoming content to a target format, such as by transcoding thecontent to different CODEC standards and resolutions. Derived contentgenerator 109 generates trick files and other types of derived contentfrom the original content, such as fast-forward and rewind trick files,movie trailers, re-formatted content, and advertising-spliced content.Content ingest manager 107 and content ingest block 105 handle thereceipt and ingest of the non-real-time content into content deliverynetwork 100, including managing ingest provisioning and life cycle andnegotiating with CPM 103 for storage locations within content library101.

Real-time manager 110 and real-time ingest block 106 have a similarfunction as content ingest manager 107 and content ingest block 105,except that these functions are performed for incoming streamedreal-time content. In addition, real-time manager 110 assigns multicastaddresses and ports for real-time content distribution. The encodedvideo program of a real-time media content asset may be sent via, e.g.,IP multicast, and real-time manager 110 may direct real-time ingestblock 106 to join the corresponding multicast and record the encodedstream based on the start and end times. The resulting files may bestored in content library 101, caching gateways 102, and/or streamingservers 117 as desired. Client devices 201 may request session andstreaming of a real-time media content asset during and/or after thereal-time ingest of that particular asset into content delivery network100, and may further perform certain trick modes on real-time contentassets as appropriate, such as rewind and pause.

MDH 113 interfaces with content delivery network 100, and the metadataand status for stored media content assets may be reported to MDH 113 soas to make the assets available for applications such as for queries by,and storage to, a unified database 901 (FIG. 9), and for asset statusand verification.

AMS 114 manages VOD asset metadata, and CMS 112 publishes the assetmetadata to AMS 114, such as via a CableLabs ADI interface. The assetmetadata of the ADI package is sent to AMS 114 while the content filesare ingested into content delivery network 100. Together, CMS 112 andRMS 111 may support both VOD content metadata (such as using CableLabsADI) and Internet video metadata (such as using Media Really SimpleSyndication, or RSS) formats.

Interface with Asset Management System: The content metadata ispublished to the Regional Asset Management Systems via the CableLabs ADIinterface. Only the metadata is sent via this interface while thecontent files are ingested into the CDN.

RMS 111 manages the licensing rights of real-time media content assets,including enabling and disabling based on licensing rights whether eachreal-time media content asset may be real-time ingested, determininglicensing start and end times of real-time media content assets, andcontrolling certain business rules such as disabling fast forward trickplay for real-time media content assets.

Data warehouse server 121 archives content usage statistics periodicallyreceived from content delivery network 100 and/or VOD backoffices 115.

Network management system 122 provides a network management interfacefor configuration, monitoring, fault detection, and alarm functions.

Content library 101 includes one or more physical computer-readablemedia for storing the media content assets ingested by content ingest105 and real-time ingest 106, along with one or more computers formanaging the input, output, and internal data management of contentlibrary 101. While content library 101 is shown as a single functionalblock in FIG. 1, in reality the various computer-readable media mayinclude multiple computer-readable media and computers distributed overa wide geographical area, especially where content delivery network 100itself services client devices 201 that are geographically diverse. Thecomputer-readable media and computers may be interconnected via, e.g.,an IP network. Thus, content library 101 may actually be a collection ofmultiple libraries that together are functionally treated as one logicallibrary. In some embodiments, content library 101 may have amulti-tiered hierarchical topology of the various computer-readablemedia.

Caching gateways 102 include one or more physical computer-readablemedia for storing at least a subset of the media content assets storedin content library 101, along with one or more computers for managingthe input, output, and internal data management of caching gateways 102.In general, media content assets may be replicated into one or more ofcaching gateways 102 as desired. Thus, while not necessarily always thecase, it may be expected that any media content assets stored in cachinggateways 102 may also be stored somewhere in content library 101. As isthe case with content library 101, the various computer-readable mediaof caching gateways 102 may also be distributed over a wide geographicalarea. While caching gateways 102 and content library 101 are shown asseparate functional blocks, physically they may share some or all of thesame computer-readable media and/or computers. Alternatively, cachinggateways 102 and content library 101 may be embodied as physicallyseparate systems.

CPM 103 may contain multiple content library 101 nodes coupled vianational and/or regional networks, such as IP networks. CPM 103 isresponsible for replicating and/or moving the media content assetsthrough various storage locations of content library 110 and/or cachinggateways 102 in a dynamic manner based on content popularity, contentusage, and/or other factors. CPM 103 is further responsible for decidingand directing which particular ones of the streaming servers 117 willstream particular content to client devices 201. This decision may bebased on, for example, the current or expected load of the variousstreaming servers 117.

The locations for all media content assets within content deliverynetwork 100 are maintained and updated by the CLS 104. Upon a sessionsetup request from a client device 201, if the requested content isalready pre-positioned or cached at a streaming server 117, the contentwill be streamed from streaming server 117 to the requesting clientdevice 117. If the content is not available at the streaming server 117,head end 190 will query CLS 104 for the locations of the requested mediacontent asset within content library 101 and/or caching gateways 102 inorder to fetch the media content asset and stream it to the requestingclient device 201.

Upon initial ingest of a media content asset, content ingest block 105and real-time ingest block 106 report the status and location of themedia content asset to CLS 104. Then, when the location is requested byhead end 190, CPM 103 fetches the reported location from CLS 104. Wherea media content asset is to be later replicated or moved, CPM 103 isresponsible for updating CLS 104 dynamically on the new media contentasset location and/or status. Thus, in general CPM 103 is responsiblefor deciding where media content assets are to be stored, and CLS 104 isresponsive to keeping track of those locations.

In the present example, multiple head ends 190 may be distributedgeographically to serve the various client devices 201, and may eachcontain the functional blocks as shown in FIG. 1, which may operate asfollows. Also, as shown by way of example in FIG. 2, each head end 190may be coupled to, and serve, only a subset of the total set of clientdevices 201. Likewise, each streaming server 117 within a respectiveheadend may be coupled to, and serve, only that respective subset ofclient devices 201. Thus, content to be delivered to a given clientdevice 201 is forwarded to and provided by one of the streaming servers117 that is coupled to the target client device 201.

Returning to FIG. 1, VOD backoffice 115 for each of head ends 190 maymanage the receipt and fulfillment of VOD requests from those clientdevices 201 that are served by the respective head end 190, includingsession setup and stream control management of VOD media content assets.In addition, VOD backoffice 115 may receive asset title and contentmetadata from CMS 112 through AMS 114, and pass business rules such astrick mode restriction to streaming server 117 upon session setup time,assist with allocating edge QAM 118 resources for VOD sessions, andassist with advertisement insertion into the stream.

For instance, in response to a VOD request from one of client devices201 served by a particular VOD backoffice 115, that VOD backoffice 115may obtain the requested VOD media content asset from content deliverynetwork 100 (if not already stored in head end 190) and cause the assetto be streamed in well-known ways to the requesting client device 201via streaming server 117 and edge QAM 118, and/or CMTS 120 (whichprovides IP-based content streaming to client devices 201). Streamingserver 117 may also include one or more computer-readable media forcaching one or more of the media content assets, especially those thathave been recently streamed by that streaming server 117.

Staging server 119 is used for Internet Protocol (IP) based streamingservices for client data devices such as personal computers and smartphones. Staging server 119 supports various content formats andprotocols, such as hypertext transfer protocol (HTTP) progressivedownload, FLASH download, and WINDOWS media streaming. Staging server119 may also use the standard HTTP-based content locate and streamingprotocol for pulling content from content delivery network 100. Inaddition, staging server 119 utilizes caching algorithms for cachinglibrary content from content delivery network 100.

Edge resource managers 116 manage bandwidth and program resources onQAMs 118. Edge resource managers 116 may support session requests frommultiple session managers. If an edge device such as edge QAM 118 orCMTS 120 announces a failure to one of the edge resource managers 116,that edge resource manager 116 may be configured to not make any sessionrelated decisions. That edge resource manager 116 may instead forward anotification to the VOD system to determine how to resolve the issue.

As stated above, the media content assets may be permanently ortemporarily stored in content delivery network 100 and/or at one or morehead ends 190 at various distributed locations, including contentlibrary 101, one or more caching gateways 102, and/or one or morestreaming servers 117. The actual locations at which each media contentasset is stored may depend upon one or more factors, such as how popularthe media content asset is to the end users, how popular the mediacontent asset is expected to be, how often the media content assets isrequested by one or more of the end users, and/or which end users haverequested or are expected to request the media content assets. Thelocations at which the media content assets are stored may changedynamically over time in responses to changes in these and/or otherfactors.

FIG. 2 shows another illustrative functional block diagram of a portionof content delivery network 100 in conjunction with head ends 190A-D andclient devices 201A-H. In this view, caching gateways 102 are shown asmultiple caching gateways 102A-E. The number of caching gateways shownhere is merely an example; there may be a fewer or greater number ofcaching gateways. Also in this example, caching gateways 102A-E areshown as being inter-coupled in a multi-tiered hierarchical topology. Inparticular, a first tier of caching gateways 102A, 102B and a secondtier of caching gateways 102C-E, are provided. Also, a third tier in thehierarchy may be considered to be head ends 190A-D. Such a hierarchicaltopology may make certain organizations of media content assets easier.For example, a tier that is more local to a head end 190 may storecopies of those content media assets that are the most requested or mostpopular (e.g., top ten) for client devices 201 of that head end 190, anda tier that is less local to that head end 190 may store copies of thosecontent media assets that are less requested or less popular (e.g., toptwenty) for client devices 201 of that head end. Using such ahierarchical caching technique, those storage nodes that are closer andmore local to head ends may not need to be as large as those storagenodes that are more global and less local to head ends. Moreover, eachtier may have its own network bandwidth resource management capability.For instance, each tier may be able to independently manage bit rates,compression, statistical multiplexing, and user limits. However, anytopology of caching gateways and head ends may be used. As mentionedpreviously, content library 101 may also have a multi-tieredhierarchical topology.

Example operation scenarios of content delivery network 100 will now bedescribed with reference to FIGS. 3-8.

FIG. 3 is a diagram of illustrative interactions between variouselements of content delivery network 100 and its environment, whenperforming ingest of non-real-time media content assets. In thisexample, metadata associated with a certain media content asset isdelivered from a content source to RMS 111 and/or CMS 112. RMS 111and/or CMS 112 generate a unique identifier for the media content asset,and provision the media content asset with content ingest manager 107.Content ingest manager 107 then instructs content ingest block 105 tobegin content ingest. Content ingest block 105 queries CPM 103, and inresponse CPM 103 determines and returns to content ingest block 105 thetarget location(s) at which the media content asset will be stored incontent library 101. Also, content ingest manager 107 periodicallyprovides the content transfer status to RMS 111 and/or CMS 112.

Next content ingest block 105 retrieves the media content asset filefrom the content provider, and also interfaces with transcoder 108 andderived content generator 109 as needed, for transcoding the mediacontent asset file and generating auxiliary trick files. The retrievedfiles and any generated trick files are saved to content library 101 atthe previously determined location(s). Content ingest block 105 reportsto CLS 104 upon completion of ingesting the content, and also to contentingest manager 107 about content transfer status. Then, content ingestmanager 107 reports, or responds to a request from, RMS 111 and/or CMS112 regarding content status.

FIG. 4 is a diagram of illustrative interactions between variouselements of content delivery network 100 and its environment, whenperforming ingest of real-time media content assets. The process issimilar, with the main difference being that real-time manager 110 isused in place of content ingest manager 107, and real-time ingest block106 is used in place of content ingest block 105. First, program guidemetadata including a real-time program schedule is delivered from acontent source to RMS 111 and/or CMS 112. RMS 111 and/or CMS 112generate a unique identifier for the real-time media content asset, andprovision the media content asset with content ingest manager 107.Real-time manager 110 then instructs content real-time ingest block 106to begin stream ingest at times defined by the real-time programschedule. Real-time ingest block 106 queries CPM 103, and in responseCPM 103 determines and returns to content ingest block 105 the targetlocation(s) at which the real-time media content asset will be stored incontent library 101. Also, content ingest manager 107 periodicallyprovides the content transfer status to RMS 111 and/or CMS 112.

Upon the scheduled start of the real-time program, real-time ingestblock 106 retrieves the media content asset stream from the contentprovider such as via IP multicast, and also interfaces with transcoder108 and derived content generator 109 as needed, for transcoding themedia content asset file and generating auxiliary trick files. Theretrieved files and any generated trick files are saved to contentlibrary 101 at the previously determined location(s). Real-time ingestblock 106 reports to CLS 104 upon completion of ingesting the stream,and also to real-time manager 110 about content transfer status. Then,real-time manager 110 reports, or responds to a request from, RMS 111and/or CMS 112 regarding content status.

FIG. 5 is a diagram of illustrative interactions between variouselements of content delivery network 100 and its environment, whenpre-positioning an entire media content asset, or a portion thereof,already stored in content library 101 to a replicated location. Thispre-positioning may be performed regardless of any client device 201request for the media content asset, and may be performed so as toreplicate the media content asset to a location that iscloser—geographically or logically—to client devices 201 that areexpected to request the media content asset. In this particular example,a media content asset (or a portion thereof) is pre-positioned fromcontent library 110 to a streaming server 117. However, this processcould alternatively be used to pre-position the media content asset fromand to any other locations, such as caching gateway 102 or elsewhere.Also in this particular example, the media content asset is a VOD asset,however any type of media content asset may be used.

New content is provisioned and ingested into content distributionnetwork 100 by RMS 111 and/or CMS 112, which publish media content assetmetadata to AMS 114. AMS 114, in turn publishes the metadata to some orall of the VOD backoffices 115. The VOD backoffice 115 associated withthe target streaming server 117 determines that pre-positioning at thestreaming server 117 is desired, and initiates a content transfercommand to streaming server 117. In response streaming server 117 sendsa content locate and transfer request to CLS 104. In response, CLS 103redirects streaming server 117 to the actual location of the desiredmedia content asset in content library 101. In response, the locatedmedia content asset (or a portion thereof) from content library 101 isreplicated to streaming server 117.

In the example of FIG. 5, pre-positioning of a media content asset byreplication occurred in response to a request from VOD backoffice 115.However, CPM 103 may alternatively initiate pre-positioning. Also,although in FIG. 5 the media content asset was pre-positioned tostreaming server 117, such pre-positioning may be made to anycomputer-readable medium in content delivery network 100 and/or outsideof content delivery network 100, such as in head end 190. For example, amedia content asset (or a portion thereof) may be pre-positioned to oneor more caching gateways 102.

Moreover, the particular location(s) to which a media content asset ispre-positioned, as well as whether or not such pre-positioning shouldoccur in the first place, may be determined responsive to adetermination that the media content asset is popular or is expected tobe popular. This determination may be made by, e.g., CPM 103 and/or VODbackoffice 115. And, the particular location(s) to which the mediacontent asset is pre-positioned may be determined based on whichgeographical locations served by content data network 100 and/or headends 190 the popularity is expected to occur. For example, anewly-released movie may be expected to be popular throughout thecountry, and so the movie (or a portion thereof) may be pre-positionedto all or most caching gateways 102 and/or VOD backoffices 115. Or, amedia content asset, or portion thereof, of particular interest to onlya certain geographic region may be pre-positioned only to one or morecaching gateways 102 and/or VOD backoffices 115 that serve thatgeographic region.

In addition, although a media content asset may be pre-positioned priorto any or substantial requests for that media content asset by clientdevices 201, the media content asset (or portion thereof) may further bereplicated to one or more additional locations based on actualexperienced requests by client devices 201 for that media content asset.And, once a media content asset has been pre-positioned or otherwisereplicated to a location, the replicated copy of the media content assetmay remain at that location for a predetermined period of time or untilit is later determined that the popularity for that media content assethas dropped below a predetermined threshold, after which time thereplicated copy may be deleted or moved to yet another location in thenetwork.

Popularity of a media content asset may be determined in many ways, suchas being based on a measured frequency of client device 201 requests forthe media content asset, determining whether the media content asset hasbeen requested by client devices 201 a sufficient number of times over apredetermined period of time, and/or based on historical or predictedfuture demand for the media content asset. Also, such determinations maybe made on a global basis (i.e., across the entire network) and/or on ageographic regional basis, and may be made more than once over time tore-determine the popularity of the media content asset and re-replicatethe entire media content asset or a portion thereof as appropriate basedon the newly-determined popularity.

Trick files may be treated like any other type of media content asset,and thus may be pre-positioned and otherwise replicated in the samemanner as any other type of media content asset. In some cases, it maybe desirable to locate trick files in the same computer-readable mediaand/or otherwise a same node of the network as their associated programcontent files. In other cases, it may be desirable to locate trick filesindependently of the location of their associated program content if itis not expected that the trick file will be as popular as the programcontent itself.

FIG. 6 is a diagram of illustrative interactions between variouselements of content delivery network 100 and its environment, whenstreaming content to a client device 201 in response to a request fromthe client device 201. In this particular example, the media contentasset is a VOD asset; however any type of media content asset may beused. Also in this particular example, the desired media content assetis streamed from a location in content library 101, however the mediacontent asset may be stored anywhere such as in caching gateway 102 orin streaming server 117.

As before, new content is provisioned and ingested into contentdistribution network 100 by RMS 111 and/or CMS 112, which publish mediacontent asset metadata to AMS 114. AMS 114, in turn publishes themetadata to some or all of the VOD backoffices 115. One of the VODbackoffices 115 optimistically processes a session setup request fromclient device 201, and in response to the request sends a session setuprequest to streaming server 117. In response, streaming server 117checks its local cache for the requested content. If the content isavailable at the local cache of streaming server 117, then streamingserver 117 will stream the content directly to the requesting clientdevice 201. If the requested content is not stored at the local cache ofstreaming server 117, then streaming server 117 sends a content locateand transfer request to CLS 104.

In response, CLS 104 redirects streaming server 117 to the actuallocation in content library 101 (or elsewhere) where the requested mediacontent asset is stored. In response to this redirection, streamingserver 117 performs content transfer of the media content asset fromcontent library 101, and streams the transferred content to therequesting client device 201.

FIG. 7 is a diagram of illustrative interactions between variouselements of content delivery network 100 and its environment, when atrick file or other type of derived content is requested to be streamedto a client device 201. In this particular example, the requested trickfile is already generated and is stored in content library 101. However,the trick file may be stored elsewhere, such as in caching gateway 102or streaming server 117.

After an initial setup request and response between client device 201and VOD backoffice 201, content from content library 101 is streamed bystreaming server 117 to client device 201. During the content streaming,the user of client device 201 requests a trick play function, such as byselecting “fast forward” on the remote control. In response to the userrequest, client device 201 sends a trick play command from client device201 to streaming server 117. In response, streaming server 117 checksits local cache for the requested trick file. If the trick file isavailable at the local cache of streaming server 117, then streamingserver 117 will stream the trick file directly to the requesting clientdevice 201. If the requested trick file is not stored at the local cacheof streaming server 117, then streaming server 117 sends a contentlocate and transfer request to CLS 104.

In response, CLS 104 redirects streaming server 117 to the actuallocation in content library 101 (or elsewhere) where the requested trickfile is stored. In response to this redirection, streaming server 117performs transfer of the trick file from content library 101, andstreams the transferred trick file to the requesting client device 201.

Later, during streaming of the trick file, client device 201 may requestthat the trick play end (in response to a user request to end the trickplay function) and that the content stream resume to the normal contentthat was streaming prior to the trick play. This request is received bystreaming server 117, and in response streaming server 117 resumesnormal content streaming to client device 201.

FIG. 8 is another diagram of illustrative interactions between variouselements of content delivery network 100 and its environment, when atrick file or other type of derived content is requested to be streamedto a client device 201. This time, the requested trick file is notalready generated and stored, and is to be generated in response to theclient device 201 request, such as by deriving the trick file from anexisting pre-stored or live media content asset. Although a trick fileis requested and generated in this example, such dynamic generation maybe performed to generate any type of media content file, such as a VODmovie or television program.

Trick files and other types of derived media content assets may bederived from original, or parent, media content assets in several ways.In one way, the derived content may be one or more portions of theoriginal content, such as where the derived content is a trick file ormovie trailer. For instance, the derived trick file may be a video filehaving every nth (n>1) video frame of the original content, such as in afast-forward trick file.

Another way to derive content is to generate a re-formatted version ofthe original content. For example, the derived content may be based onthe original content except at a lower video and/or audio resolution,different video frame size, being transcoded using a different CODEC, orconfigured to be played at a different bit rate or frame rate. This typeof derivation may be desirable where, for example, the client device 201that will be receiving the derived content is not compatible with theformat of the original content.

Still another way to derive content from original content is to addcontent to the original content, such as by splicing in local ornon-local advertising. This may be useful where, for example, it isdesired to insert local advertising relevant to the geographical regionin which client device 201 that will be receiving the derived content islocated.

Any or all of these types of derivation may be used separately ortogether in any combination to provide a derived media content assetfrom an original live or stored media content asset.

In the example of FIG. 8, after an initial setup request and responsebetween client device 201 and VOD backoffice 201, content from contentlibrary 101 is streamed by streaming server 117 to client device 201.During the content streaming, the user of client device 201 requests atrick play function, such as by selecting “fast forward” on the remotecontrol. In response to the user request, client device 201 sends atrick play command from client device 201 to streaming server 117. Inresponse, streaming server 117 checks its local cache for the requestedtrick file. If the trick file is available at the local cache ofstreaming server 117, then streaming server 117 will stream the trickfile directly to the requesting client device 201. If the requestedtrick file is not stored at the local cache of streaming server 117,then streaming server 117 sends a content locate and transfer request toCLS 104.

In response, CLS 104 determines that the trick file is not stored incontent library 101 (or elsewhere), and sends a trick file locateresponse to streaming server 117 indicating this. In response to thetrick file locate response, streaming server 117 sends a trick filetransfer request to content library 101, which in turn sends a trickfile object request to real-time ingest 106. In response, real-timeingest 106 sends a trick play generation request to derived contentgenerator 109, identifying the particular trick file that is needed, andstreams the transferred trick file to the requesting client device 201.In response to the trick play generation request, derived contentgenerator 109 generates the trick file, by deriving it from originallive or store content such as described previously, and sends it (or anidentifier that identifies the newly-generated trick file) back toreal-time ingest 106 in the form of a trick play generation response. Inthis example of FIG. 8, the derived content is a trick file. However,the derived content may be any type of derived content, such as a movietrailer, reformatted content, or content spliced with local advertising.

In response to the trick play generation response, real-time ingest 106sends a trick file object response indicating or including the trickfile to content library 101, and then in response to that contentlibrary sends a trick file transfer response to streaming server 117.Content library 101 may also store the newly-generated trick file in theevent that it is requested again. Next, streaming server 117 beginsstreaming the trick file to client device 201.

Later, during streaming of the trick file, client device 201 may requestthat the trick play end (in response to a user request to end the trickplay function) and that the content stream resume to the normal contentthat was streaming prior to the trick play. This request is received bystreaming server 117, and in response streaming server 117 resumesnormal content streaming to client device 201.

In other embodiments, a command may be generated by client device 201,with or without user intervention, that requests derived content (trickfile or otherwise). In such a situation, FIGS. 7 and 8 might bemodified, for example, by the “trick play command” being replaced withthe more generic “derived content request,” which may be sentautomatically responsive to establishing a session. In the derivedcontent request, client device 201 may request that a particular type offormatted content be provided, such as a particular coding format, videoframe size, bit rate, video and/or audio resolution, etc. The type offormat requested may depend upon the type of device that client device201 is. For example, where client device 201 is a smart phone with acellular connection (directly or indirectly) to streaming server 117,client device 201 may request a low-resolution and/or low bit-rateversion of the content.

As previously discussed, one of the locations at which a media contentasset may be stored is at a streaming server 117 of a head end 190.While this may occur through normal replication of the asset fromcontent library 101, it is also possible that the media content assetmay be stored only locally at streaming server 117 and not centrally orglobally at content library 101. In such a case, the ingested mediacontent asset may either be transferred from content library 101 tostreaming server 117 without maintaining a copy at content library 101,or the media content asset may be ingested and stored directly instreaming server 117 without first being stored in content library 101.Any of these situations may be determined and controlled by, forexample, content propagation manager 103. In the latter situation, amedia content asset may be stored at one or more streaming servers 117but not necessarily at content library 101 when the media content assetis considered a local media content asset. That is, a media contentasset that is expected to have interested viewers only in one or morelocal geographic regions, or an asset that is licensed only to be viewedin one or more local geographic regions rather than nationwide.

For example, a local semi-professional baseball game may be recorded andprovided to viewers in northern California. It would not be expectedthat many viewers anywhere other than northern California would beinterested in viewing that game. Thus, it would not necessarily beefficient to store a media content asset showing that game in contentlibrary 101 or at head ends 190 or caching servers 102 not located innorthern California. Therefore, it might be preferable in such asituation to normally store the asset only locally in one or morenetwork locations in or near northern California.

However, there may be an occasion where someone outside of northernCalifornia (in the above example) would like to view the game. Toaccomplish this, the network may be configured to allow bi-directionalsharing between head ends 190 that serve different geographic regions,or in fact between any two head ends 190 in the network. FIG. 9 is afunctional block diagram of an example of how content delivery network100 may be used to perform such bi-directional local content sharing.

In the example of FIG. 9, there are multiple content ingest managers107, real-time ingest managers 110, content ingest blocks 105, andreal-time ingest blocks 106 that are part of content delivery network100, each serving a different geographic region. For instance, FIG. 9shows that a first geographic region is served by content ingest blockCI1, real-time ingest block RTI1, content ingest manager CIM1, andreal-time ingest manager RTM1. Likewise, a second geographic region isserved by content ingest block CI2, real-time ingest block RTI2, contentingest manager CIM2, and real-time ingest manager RTM2. Also, a firsthead end 190 serving the first geographic region includes VOD backofficeVB1 and streaming server SS1, whereas a second head end 190 serving thesecond geographic region includes VOD backoffice VB2 and streamingserver SS2. Each geographic region also serves their own sets of clientdevices 201, represented illustratively in FIG. 9 as client device C1for the first geographic region and as client device C2 for the secondgeographic region.

The first and second geographic regions may be geographically separatefrom each other, such as being in different cities, counties, states, orcountries. In terms of distance, the first and second geographic regionsmay be close to each other or far from each other, such as at least fivehundred miles apart from each other.

A unified database (UDB) 901 for storing metadata describing mediacontent assets is communicatively coupled (uni-directionally orbi-directionally) to equipment serving both the first and secondgeographic regions. For instance, as shown in FIG. 9, UDB 901 is coupledto content ingest manager CIM1, real-time ingest manager RTM1, contentingest manager CIM2, real-time ingest manager RTM2, VOD backoffice VB1,and VOD backoffice VB2. Any or all of these blocks are capable ofquerying and updating the data stored in UDB 901.

The media content assets for which metadata is stored in UDB 901 mayinclude local media content assets received by a content source thatserves or is located in the first or second geographic region, such asLocal Content Source 1 and Local Content Source 2 in FIG. 9. These localmedia content assets are received into content ingest manager CIM1,real-time ingest manager RTM1, content ingest manager CIM2, or real-timeingest manager RTM2.

When a local media content asset is ingested at one of the geographiclocations, the local media content asset (either real-time ornon-real-time) may be stored at a head end 190, such as the head end 190serving that geographic location. In particular, the media content assetmay be stored at the streaming server or otherwise at acomputer-readable medium to which the streaming server has access. Inaddition, the metadata for that local media content asset may be passedon to UDB 901. Because UDB 901 shares access to multiple geographicregions, such as the first and second geographic regions of FIG. 9, themetadata for a media content asset may be available to any of thosegeographic regions even though the media content asset itself may onlybe stored at one of those geographic regions.

For example, if a local media content asset is ingested by contentingest block CI1, the local media content asset may be stored atstreaming server SS1, and the metadata for that local media contentasset may be stored in UDB 901, such as via a path from content ingestblock CI1 to content ingest manager CIM1 to UDB 901. In this example,the local media content asset is a VOD asset. If client device C1 wishesto view the local media content asset, then VOD backoffice VB1 can lookup the metadata for that asset in UDB 901 and determine from CLS 104that the asset is stored at streaming server SS1. The asset is thenstreamed to client device C1 from streaming server SS1. If client deviceC2 wishes to view the local media content asset, then VOD backoffice VB2can also look up that same metadata for the asset in UDB 901 anddetermine from CLS 104 that the asset is stored at streaming server SS1.The asset can then be transferred to streaming server SS2, such as via acaching gateway 102. Streaming server SS2 then streams the asset toclient device C2. Thus locally-stored content may be shared betweendifferent geographic regions of the network.

An example of interactions between various equipment when a local mediacontent asset is shared between streaming servers is shown in thediagram of FIG. 10. Metadata for a local media content asset is receivedby content ingest block CI1 (for a non-real-time asset) or real-timeingest block RTI1 (for a real-time asset). The metadata is thenforwarded by content ingest manager CIM1 or real-time manager RTM1 toUDB 901 for storage. The actual local media content asset may beingested by content ingest CI1 or real-time ingest RTI1, and stored atstreaming server SS1 and/or a caching gateway 102 local to streamingserver SS1.

At some future point in time, the metadata for that local media contentasset is replicated, in whole or in part, from UDB 901 to VOD backofficeVB2, either spontaneously or in response to a request for the localmedia content asset by VOD backoffice VB2, and some or all of themetadata for that asset may be passed on to client device C2, such as inthe form of an electronic program guide indicating the local mediacontent asset as an available choice. In response to a session setuprequest from client device C2, such as by the user selecting theindicated local media content asset from the program guide, VODbackoffice VB2 sends a content locate request to its local cachinggateway 102 (not necessarily the same caching gateway at which the localmedia content is stored). In response, caching gateway 102 performs acontent check with CLS 104, which returns the location of the desiredlocal media content asset to caching gateway 102 and then on to VODbackoffice VB2. VOD backoffice VB2 then sends a session setup responseto client device C2 and requests that the found local media contentasset be replicated to streaming server SS2. The transfer is performed,and streaming server SS2 streams the local content media asset to clientdevice C2.

Alternatively, rather than streaming the replicated media content asset,it may be possible that client device C2 desires a different format ofthe media content asset. In that case, either during or after sessionsetup, client device C2 may request that the media content asset be in aparticular format. If the particular format is not already pre-stored,then similar to the FIG. 8 embodiments, derived content generator 109may derive the requested version of the media content asset such thatthe derived version is streamed to client device C2.

The process of FIG. 10 may also be reversed, such as where the localmedia content asset is initially received, ingested, and stored at thesecond geographic region and transferred to the first geographic region.And, as in the other embodiments described herein, any of the mediacontent assets shared between video-on-demand systems may be live mediacontent assets or non-live media content assets.

Thus, various systems, apparatuses, methods, and software have beendescribed by way of example for using a network to efficientlydistributing media content assets from a virtually unlimited contentlibrary and/or other storage to a plurality of client devices. Inaddition, it has been shown how bi-directional local content sharingbetween head ends may be accomplished, as well as dynamic distributionand generation of media content assets within the network.

1. A method for sharing media content assets between video-on-demand systems of a service provider network, the method comprising: receiving first media content and associated first metadata at a first video-on-demand system, the first video-on-demand system being configured to stream media content assets to a first plurality of client devices; generating a first media content asset representing the first media content; sending the first metadata to a database, retrieving the first metadata from the database by a second video-on-demand system configured to stream media content assets to a second plurality of client devices to which the first video-on-demand system is not configured to stream media content assets; sending, by the second video-on-demand system, a request for the first media content asset, the request being based on the first metadata; and responsive to the request from the second video-on-demand system, replicating at least a portion of the first media content asset to the second video-on-demand system.
 2. The method of claim 1, wherein the first media content asset is a live media content asset.
 3. The method of claim 1, further comprising streaming, by the second video-on-demand system, the replicated copy of the at least the portion of the first media content asset to at least one of the second plurality of client devices.
 4. The method of claim 1, further comprising sending, by the second video-on-demand system, data to the second plurality of client devices, the data being based on the retrieved first metadata.
 5. The method of claim 1, further comprising receiving, by the second video-on-demand system, a client request from one of the second plurality of client devices, wherein sending the request for the first media content asset is performed responsive to the client request.
 6. The method of claim 1, wherein the first and second video-on-demand systems are geographically separate from each other.
 7. The method of claim 1, further comprising: receiving a second media content asset and associated second metadata at the second video-on-demand system; generating a second media content asset representing the second media content sending the second metadata to the database; retrieving the second metadata from the database by the first video-on-demand system; sending, by the first video-on-demand system, a request for the second media content asset, the request being based on the second metadata; and responsive to the request from the first video-on-demand system, replicating at least a portion of the second media content asset to the first video-on-demand system.
 8. A video-on-demand network for sharing media content assets between video-on-demand systems, the video-on-demand network comprising: a first computer-readable medium; a database; and a first video-on-demand system configured to stream media content assets to a first plurality of client devices, wherein the first video-on-demand system is further configured to: receive first media content and associated first metadata, generate a first media content asset representing the first media content, and send the first metadata to the database, wherein the network is configured to replicate at least a portion of the first media content asset to a second video-on-demand system having access to the database and configured to stream media content assets to a second plurality of client devices to which the first video-on-demand system is not configured to stream media content assets, the replication being responsive to a request from the second video-on-demand system for the first media content asset.
 9. The video-on-demand network of claim 8, wherein the second video-on-demand system is further configured to stream the replicated copy of the at least portion of the first media content asset to at least one of the second plurality of client devices.
 10. The video-on-demand network of claim 8, wherein the second video-on-demand system is further configured to send data to the second plurality of client devices, the data being based on the first metadata stored in the database.
 11. The video-on-demand network of claim 8, wherein the second video-on-demand system is further configured to send the request for the first media content asset responsive to receiving a client request from one of the second plurality of client devices.
 12. The video-on-demand network of claim 8, wherein the first and second video-on-demand systems are geographically separate from each other.
 13. The video-on-demand network of claim 8, wherein the second video-on-demand system is further configured to: receive second media content and associated second metadata; generate a second media content asset representing the second media content; and send the second metadata to the database.
 14. The video-on-demand network of claim 13, wherein the first video-on-demand system is further configured to: retrieve the second metadata from the database; and request the second media content asset, the request being based on the retrieved second metadata.
 15. The video-on-demand network of claim 14, wherein the first video-on-demand system is further configured to: receive a replicated copy of at least a portion of the second media content asset; and stream the replicated copy of the at least the portion of the second media content asset to at least one of the first plurality of client devices.
 16. A system for sharing media content assets between first and second video-on-demand systems each serving a different plurality of client devices, the system comprising: a computer; and a computer-readable medium, wherein the computer is configured to: receive a first media content asset from the first video-on-demand system, and store the received first media content asset in the computer-readable medium, wherein the first video-on-demand system is configured to stream media content assets to a first plurality of client devices, receive a request from the second video-on-demand system for the first media content asset, and responsive to the request from the second video-on-demand system, replicate at least a portion of the first media content asset to the second video-on-demand system, wherein the second video-on-demand system is configured to stream media content assets to a second plurality of client devices to which the first video-on-demand system is not configured to stream media content assets.
 17. The system of claim 16, wherein the first plurality of client devices are located in a different city from the second plurality of client devices.
 18. The system of claim 16, wherein the first and second video-on-demand systems are located at least five hundred miles from each other.
 19. The system of claim 16, wherein the computer is further configured to: receive a second media content asset from the second video-on-demand system, and store the received second media content asset in the computer-readable medium, receive a request from the first video-on-demand system for the second media content asset, and responsive to the request from the first video-on-demand system, replicate at least a portion of the second media content asset to the first video-on-demand system.
 20. The system of claim 16, wherein the first media content asset is a live media content asset. 